WordNet (r) 3.0 (2006):

treasure house
    n 1: a storehouse for treasures

Moby Thesaurus II by Grady Ward, 1.0:

87 Moby Thesaurus words for "treasure house":
   Fort Knox, Golconda, archives, armory, arsenal, attic, bank,
   basement, bay, bin, bonded warehouse, bookcase, box, bunker,
   bursary, buttery, cargo dock, cash register, cashbox, cellar,
   chest, closet, coffer, coin box, conservatory, crate, crib,
   cupboard, depository, depot, dock, drawer, dump, eldorado,
   exchequer, fisc, glory hole, godown, gold depository, gold mine,
   hold, hutch, library, locker, lumber room, lumberyard, magasin,
   magazine, mine, money chest, penny bank, piggy bank, pork barrel,
   public crib, public till, public treasury, public trough, rack,
   repertory, repository, reservoir, rick, safe, safe-deposit box,
   shelf, stack, stack room, stock room, storage, store, storehouse,
   storeroom, strong room, strongbox, subtreasury, supply base,
   supply depot, tank, till, treasure house, treasure room,
   treasure trove, treasury, vat, vault, warehouse, wine cellar